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Reno

wrote in news:14df1c20-ea2d-4218-a51e-
:

I have been looking for something that probably doesn't exist for
reasons I don't know.

I am trying to find out if there is such a thing as a heat exchanger
for a dryer that would attach like a humidifier to a furnace?

One thing that would recover the heat is too duct the dryer exhaust to an
HRV - Heat Recovery Ventilator. There would be a few problems to solve
the main one being that HRV's use very narrow spaces for air flow and
lint would plug them in no time at all. So you would first have to design
a way to clean all lint from the air - screens and filters. HRV's have
filters in them but they couldn't handle dryer lint without plugging
right away.

HRV's accomplish the heat exchange by running in and out air through
narrow spaces, alternating warm and cold spaces so the incoming air
channels have an out going air channel on both sides, etc. The spaces are
about 1/16 th inch wide by 12" by 12".

Another major issue would be balancing the airflow into house with
airflow out - HRV's have 2 fans, one blowing in and one blowing out and
they should be balanced fairly closely or you compromise overall house
ventilation with all of the attendant problems.

Up here, in Canada, HRV's cost around $800 plus installation.

I once thought I could design an HRV myself but there are way too many
issues to deal with, especially up here where winters are -20 to -30 C
for 6 months. I have a 2 heat exchanger geothermal heating system with 2
HRV's and they work great - house humidity is way too low in the winter
if I run them too much. MY HRV's come with defrost settings if the
incoming -30 air tends to freeze the units, drains for condensate, timers
built into switches and the dehumidistat, insulated ducting, etc. Fairly
complicated. They are claimed to be about 80% efficient.

You could look for a commercial HRV - maybe there is such a thing - there
must be an application requiring wider slots. The slots are in the heat
excahnger which is removable for cleaning. Mine are plastic so I clean
them with a pressure washer. If you had enough screens and filters maybe
the lint problem would be reduced so cleaniong the exchanger every once
in a while would be feasible. On mine the slots are so narrow and long
that I couldn't blast clumps of lint out.